/*  MailDecrypter, version 1.0.0
 *  (c) 2007 Sven Hecht
 *
 *  MailDecrypter is freely distributable under the terms of an MIT-style license.
 *  For details, see http://sven.hecht.googlepages.com/index.html
 *
/*--------------------------------------------------------------------------*/

var MailDecrypter = Class.create();
MailDecrypter.prototype = {
  initialize: function()
  {
  	this.keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
  },
  
  Decrypt: function(input)
  {
  	var output = "";
		 var chr1, chr2, chr3;
		 var enc1, enc2, enc3, enc4;
		 var i = 0;

		 // remove all characters that are not A-Z, a-z, 0-9, +, /, or =
		 input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");

		 do {
				enc1 = this.keyStr.indexOf(input.charAt(i++));
				enc2 = this.keyStr.indexOf(input.charAt(i++));
				enc3 = this.keyStr.indexOf(input.charAt(i++));
				enc4 = this.keyStr.indexOf(input.charAt(i++));

				chr1 = (enc1 << 2) | (enc2 >> 4);
				chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
				chr3 = ((enc3 & 3) << 6) | enc4;

				output = output + String.fromCharCode(chr1);

				if (enc3 != 64) {
					 output = output + String.fromCharCode(chr2);
				}
				if (enc4 != 64) {
					 output = output + String.fromCharCode(chr3);
				}
		 } while (i < input.length);
			
	   return output;
  },
  
  Encrypt: function(input)
  {
	   var output = "";
	   var chr1, chr2, chr3;
	   var enc1, enc2, enc3, enc4;
	   var i = 0;
	
	   do {
	      chr1 = input.charCodeAt(i++);
	      chr2 = input.charCodeAt(i++);
	      chr3 = input.charCodeAt(i++);
	
	      enc1 = chr1 >> 2;
	      enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
	      enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
	      enc4 = chr3 & 63;
	
	      if (isNaN(chr2)) {
	         enc3 = enc4 = 64;
	      } else if (isNaN(chr3)) {
	         enc4 = 64;
	      }
	
	      output = output + this.keyStr.charAt(enc1) + this.keyStr.charAt(enc2) + 
	         this.keyStr.charAt(enc3) + this.keyStr.charAt(enc4);
	   } while (i < input.length);
	   
	   return output;
  }
}